Caoimhe uses the same litter tray as the kittens but the two Sąsaigich (the other moggy girls came from Sąsaig, just down the road), Beileag and Buidheag, don't use litter trays at all, they always go outside.
Good point about the type of litter. It seems to me based on observation that the reason that they do like the duvet as a litter tray is because they can paw it as it is so very soft and other fabrics don't attract them. Ticking them off and putting them on the litter tray and shutting them in the bathroom for a minute seems to be working slowly - they get rewards of cuddles and praise afterwards. They can't use the litter tray if they think anyone is looking at them.
I think we will get there given perseverance.
The poor dog is having a crisis. He remembers that a kitten defiled his dog bed and the trauma keeps coming back to him so he turns tail and doesn't want to use it, despairingly. He just turns in circles and prepares to sleep on the floor or head back downstairs, unless Janet orders him to go into it. Every last bit of bedding is going through the wash hopefully just in case his sensitive nose is picking up some tiny lingering trace of Essence de Chat (Boladh Piseige).